Rubber-faced paving and like block



Nov.3,l925. 1,560,174 GAISMAN RUBBER FACED PAVING AND LIKE BLOCK Filed March '7. 1923 2 Sheets-Shdt' l Nov. 3, 1925. 1,560,174

' L. GAISMAN RUBBER mama PAVING AND LIKE BLOCK Filed March v, 1925 2 Sheets-Sheet 2 77 I m /,V// '1, 7 14 \s i Patented Nov. 3, 1925.

PATENT OFFICE LUCI-IIIGAISIAN, Q1 HOOLEY HILL, NEAR MANCHESTER, ENGLAND.

RUBBER-FAGED PAVING AND LIKE BLOCK.

Application filed March 7, 1923. Serial at. 623,388..

To all whom it may concern:

Be it known that LUCIEN GAISMAN, a citizen of Switzerland, residing at Hooley Hill, near Manchester, England, has invented new and useful Improvements in Rubber- Faced Paving and like Blocks, of which the following is a specification.

This invention refers to rubber-faced paving blocks for road paving and like purtop of the block by poses, and the invention has particular reference to rubber-faced blocks of the kind wherein the rubber facing is secured to the means of undercut projections and recesses. x

Heretofore, the projections have extended all round the rubber slab on its underface, or they have extended along two opposite sides or edges only in the form of continuous flanges, the recesses in the block corresponding and no portion of the top edges of the block against which the projections fit lyingflush with the outer vertical edges of the rubber slab.

The projections and recesses have been undercut in vertical cross section, and the keying of the rubber to the block has necessitated the interlocking of the projections with the recesses by pressure or im act, or by sliding the projections endwise into the recesses. In requiring to spring the projections into the recesses the-projections have to be comparatively thin and flexible, or the bevel steep. and/or keys are required between the slab of one block and that of the next to help to hold the projections in the recesses. When the slab is adapted to be interlocked with the block by forcing or sliding the projections on to parallel opposite edges, the slab is held against lateral movement in two directions only.

The main object of this invention is to provide a rubber slab and block with under cut projections and recesses which can be caused to interlock without requiring to rely on great pressure or impact; without requirinn the projections to be thin and flexible; without requiring to use keys: and without requiring to slide the projections endwise into the recesses. A further object is to provide a slab which, while firmly held downwards and against lateral movement along its edges, is also held in all directions against lateral disturbance ordisplacement, andconsequent friction, on the under-face of the slab. A further object is to apply to large blocks a rubber facing composed of two or more slabs.

According to the invention, the rubber slab is formed on its underface and at or near and along its edges with a series of downwardly extending segmental. projections, and in the top edges of the block a series of segmental recesses is formed, these latter being undercut and corresponding in shape, size, position and number to the projections. The projections and recesses will each preferably be part of a circle in plan and while the slab and projections may be of a tough and of a fairly elastic quality, the underface of the slab and/or the projections can be of a tougher or harder quality of rubber. Further, the projections will be spaced so that the distance from projection to projection along the edges of the slab will be of the same order of magnitude as the mean diameter of a projection, whilst the mean radius of a projection will be approximately of the same order of magnitude as the depth or height of a projection. The height of a projection will preferably be greater than the thickness of the slab proper. These proportions are, of course, approximateand may be modified within limits which will not interfere with the secure anchoring of the slab.

\Vith the rubber slab and block thus made they allow of the slab being fitted to the block without having to use great pressure or impact, and without requiring to slide the slab endwise, the projections being adapted to be readily moved outwards by hand to'allow them to enter the recesses sideways, and,

when in the recesses, holding the slab against movement in all directions, part of the upper portion of the block extending to and lying flush with the edges of the slab and also lying between the projections, and those parts of the block surrounding each recess anchoring the rubber to the block in a vertical plane parallel withthe edge of the slab and also in vertical planes at an angle to the edge ofthe slab.

To further help in securing the slab against movement, some or all of the projections may be moulded or formed with a slight inward set so that after they have have no inward set, and tend to return to the normal or original positions, they grip the block. The projections at each corner will preferably be rather more than a quarter of a circle and less than a semi-circle in plan, while the intermediate projections will be a semi-circle, or slightly more than a semicircle in plan. Other shapes may be employed so long as an equivalent cross-sectional area and interlock are provided.

According to the further improvements, the nnderface of the rubber slab, instead of being fiat and parallel with its upper face, is formed convex, whilst the top face of the block is formed concave (orvice versa), or the said. faces are formed With lnter-engaging corrugations, the .purpose of which is to cause the forces dueito traflic acting upon the rubber and tending to spread the rubber to be balanced by the resistance offered by the form of the surface of contact of the rubber and block. In a modification, the contacting surfaces of the slab and block may be arched in one direction only, and usually lengthways of the slab and block.

In applying the invention to a pavin block of the usual dimensions (9x4x3" the arrangement of the projections and recesses is suflicient to hold those parts of the slab within the area enclosed by the projections against movementin all directions, but in applying the invention to blocks of larger surface area, say twice or three times wider than that of the said ordinary ,paving block, the provision of projections and recesses along the edges of the slab and block while effective in holding the slab to the blockalong'such edges and preventing relative endwise movement of such edges, 'does not afford sufiicient resistance to movement of the central parts of the slab.

According to the further features of this invention, a series of rubber slabs, made as aforesaid to the ordinary paving block size, is applied to a single large block, the slabs lying side by side and completely covering.-

the top face of the block. The block. which is a multiple of the width of the slabs. is formed with undercut recesses along its top edges, and also with an undercut recess or recesses in its top face, those in its top edges being segmental, and the recess or recesses in the top face of the block being circular in plan. The improvements may be a plied to other than wood paving blocks, inc uding moulded blocks, and when so applied the slab may be connected to the block in the pro-- cess of molding the block. Upon the accompanying drawings, Fig.1 illustrates in perspective the underside of'a rubber slab, and v Fig. 2 a like view of the top part of a paving block made according to one example of the invention.

tacting faces.

Fig. 3 illustrates in perspective the same rubber slab and block interconnected.

Fig; 4 illustrates a plan of the slab and block. I

'Fig. 5 illustrates a part exterior and part sectional elevation of the slab alone.

Fig. 6 illustrates in perspective the rub;

Fig. 12 illustrates an inverted plan of a further modification of the rubber slab.

Figs. 13 and 14 illustrate longitudinal sectional elevations and Figs. 15 and 16 illustrate transverse sectional elevations of the improved paving block and rubber slab when formed concave and convex (or arched) on their con- Fig. '17 illustrates a transverse sectional elevation of the block' and slab when provided with inter-engaging corrugations on theircontaetine' surfaces.

Fig. 18 illustrates an inverted plan of the slab shown in Figure 17.

Figs. 19, 20 and 21 illustrate cross-see tions in part of two adjacent blocks ,and show the manner in which the blocks can be laid side by side. In Fi re 21 the slab portions overhang and a ut in order to space left between the bridge over any blocks.

section of a moulding box and three rubber slabs at the bottom of the box, the slabs being inverted.

Fig. 23 illustrates a part longitudinal sectional elevation ofa concrete block moulded on to the three rubber slabs in the box shown in Figure 22.

Referring now to Figures 1 to 4, A is the rubber slab. and B the paving block. The slab is similar in shape and size in plan to slab. In the example shown, there are six projections, one at each end or corner and one arranged centrally along each longitudinal edge of the slab. Each side pro-.

jection is semi-circular in pan and each corner pro ection 1s a quarter of a circle 1n plan, or 1s preferably more than a quarter Fig. 22 illustrates perspectively a cross "the block, or, as hereinafter explained, .is

and less than asemi-circle in plan, see Figedge of the slab, thus giving to the projection and recess a half-dovetall and part-cone like shape in elevation and producing the desired interlock between the slab and block. In thus forming the projections and recesses. they each provide a lock in a plane parallel with the adjacent edge of the slab, and also I in planes lying at an angle to said edge. And

by making the corner projections of the slab more than 'a quarter circle and less than a semi-circle in plan, the corners of the slab are more efiectually prevented being lifted up than is the case when the corner projections are a quarter circle only in plan. That 1 is to say, the block lies around a greater portion of each corner'projection and therefore extends nearer the corner of the slab.

The intermediate projections along the edges of the slab maybe rather more than a semi-circle, see Figure 11, thereby increasing the locking effect of such projections.

In addition to the slab being held from end to end against lateral disturbance, each section of the slab surrounded by projections is also held against lateral distubance.

Each projection may be moulded to normally assume in vertical cross section the position shown in Figure 8 relatively to the slab, or each projection may be moulded to normally assume the position in vertical cross section shown in Figure 9. In the case of Figure 9, the projections on requiring t0 engage the recesses in the block B, will have first to be moved outwards slightly so that when the slab is on the block, the projections, 1n tending to return to the normal, will grip the block and thereby further help to secure the slab to the block. After belng moved outwards and when on the block, the projections lie flush on their flat outer faces with the vertical faces of the block, see dotted lines in Figure 9.

To avoid any distortion of the upper face of the rubber slab when the projections are made as 111 Figure 9, the slab is moulded to an appropr ate form which will ensureof the slab being level after the projections have been moved outwards.

In the case of Figure 10 the recesses in the block will have the same shape exactly as the projections, the-keenerangles of the' back part ofthe ing the anchoring action.

pro ection and recess help- In Figure 8 the lower face of the projection is at rlght angles to the outer face. In Figure 9 the same is the case when the projection is engaged in the block recess. In Figure 10 the OWer face is at a less angle and the bevelled face is less steep than the bevelled face of the projections shown in Figures 8 and 9. v

I In the case of wood and like paving blocks the recesses Will be cut in the blocks by suitable tools. In the case of composition or moulded blocks, the recesses may be formed in the moulding operation, and infact, the

rubber slab may be used to produce the recesses. That is to say, the improved rubber slab can be placed in the moulding box with the projections upwards, see Figure 6, and on the concrete or other composition being run into the box, and allowed to set hard, the projections of the slab produce the desired recesses in the block and the slab becomes anchored to the block.

When the projections a, a on the slab are given an inwar set as shown in Figure 9 and the block is formed by moulding, a small stamping or strip-of metalc may be placed between the two 0 posite side projections, see Figure 6, where y said projections will be held apart to the extent 0 neutralizing the set and putting the projections in tension, so that, on the concrete setting and engaging the said projections, these latter will offer a firm resistance to displacement. In Figure 7 the whole of the projections .are'shown held separated by a frame or angular in plan and the intermediate projections are approximately rectangular in plan. The shapes of projections shown in Flgures :11 and 12 will usually apply to rubber slabs Instead of the used with moulded blocks. segmental projections being on the slab they maybe on the block and the recesses in the slab.

In order to prevent or reduce friction between the rubber slab and block. the upper face of the block and lower face of the slab, other than the projections, may be made concave and convex respectively, see Figures 13 to 16. Under the load due to vehicular traflic the rubber tends to spread or creep, but owing to the curvature of the contacting faces of the rubber and block, the forces acting to spread the rubber are practically balanced and the rubber is merely compressed, and little or no movement of the rubber over the surface of the block takes place.

Instead of making the contacting surfaces of the rubber and block concave and convex, they may be corrugated, see Figures 17 and 18. The corrugations may be applied to the concave and convex surfaces.

The slab may be the same size in plan as I the block and therefore lie flush on all its I I edges with the vertical sides of. the, block, I

sition when the-projections of two slabs lie face to face, a dowel may be arranged between the two projections, see Figure 20.

The improved rubber slab may be made of one quality or hardness of rubber throughout, or it may be built up or composed of layers of rubber of differentqualities or degrees of hardness. For example, while the slab proper may be of a tough but fairly elastic quality, its underface and/or the slab projections can be made-of a tougher or harder quality of rubber. This feature is very important as it helps greatly in the secure fixin of the slab to the block, while not interferlng-with the elasticity of the slab proper. I

To afford an elastic contact between the bottom of each 'rojection and its recess, the projection may e faced with elastic rubber, the hard rubber thus lying between the resilient rubber slab and the facing of elastic rubber atits lower end. r

Referring to Fig. 23, three rubber slabs are fitted to a single block, which is a multiple in width of an ordinary wood paving block.

The slabs will preferably be applied to moulded blocks, and during the process of moulding the block. The required number of slabs are first placed in the moulding box with the segmental projections uppermost, see Figure 22. The cement, concrete or other moulding material'is then placed in the box to mould the desired block 'on to the slabs, the slab projections serving to form undercut recesses in tl block, so that on removin the block from the box, the slabs are efi ectually locked to the block.

The recesses in the block will correspond to the shape of a slab projection, or to that of two slab projections side by side.

As in the case of the small block, the projections on each slab, may be formed with a slight inward set, and be held separated by metal or other fitments during the mouldin operation.

0 slab projections will preferably be hard or tough and the slab proper less hard or tough. The underface of the slab may be harder or tougher than the upper part of the slab. The lower part of each projection may also be softer and more elastic than the other parts of the projection. The slabs may be formed to a thickness slightly greater on one edge than on the other and thereby collectively produce a camber, see Figure 23.

In the case of wood blocks, the segmental projections of the slabs may be forced into the recesses of the block or vulcanized'at a low temperature on to the wood with the aid of a low temperature vulcanizing accelerator. 1

Rubber cement may be used between the slabs and block to further help to fix the slabs tothe block.

By applying two or more rubber slabs with pro ections at the edges only to one block, the difficulty is overcome that would be present if a single slab with central dove-. tail shaped projections were used, since itwould be difiticult, if not impossible, to force the wider ends of the projections out of the moulds and into the recesses, unless the quality or taper of the projections was made to suffer. Further, to mould a slab with central dovetail projections could only be done by the use of'costly moulds and would also render the rate of production very slow. With the slabs made as described they can be cheaply and rapidly produced.

Although the rubber slabs will preferably be the same length and width as the ordinary wood block, they may be made longer or shorter to suit blocks which are of'lar er or smaller dimensions in length and wi th than the ordinary woodblock. In all cases however the projections and recesses of the slab and block will be of the same order of magnitude as in the case of the ordinary size of wood block.

The slabs and single large blocks may be made concave and convex on their contacting surfaces, or-cor-rugated, as in the case of th e small block.

The improved rubber-faced blocks may be applied to other than road paving, and in such case the block may be of less depth than a paving block.

What-I claim is 1. A paving block having in its top edges and at each corner segmental undercut recesses, the recesses opening on to the side and end faces of the block and those in the edges approximately semi-circular in plan and those at the corners being rather more than a quarter of a circle and less than a semi-circle in plan, in combination with a rubber slab of like proportions in plan to theto face of the block and having on its under ace and along its lower edges and bot tom corners, segmental projections corresponding in shape and size with the recesses in the block, and on the slab being applied to the block completely filling same and preventing end or sideways movement of the slab in all directions, as set forth.

2. A pavin block having in its top edges including eac top corner a series of segmental undercut recesses, in combination with a rubber slab of like proportions in plan to the top face of the block, and having on its underface and along its edges a series of downwardly extending projections correspondin to and engaging with the recesses in the block, said recesses and projections being spaced apart at'distances approximating to the same order of magnitude as the mean diameter of a projection and (the mean radius of a projection being approximately of the same order of magnitude as the depth or height of a projection, which is greater than the thickness of the slab, as set forth.

3. A paving block having in its top edges and at each corner segmental undercut recesses, the recesses opening on to the side and end faces of the block and those in the edges a quarter. of a circle an approximately semi-circular in plan and those at the corners bein rather more than less than a semicircle in plan, in combination with a rubber slab of like projections in plan to the top face of the block and having onits underface and along its lower edges and bottom corners, segmental projections corres nding in shape and size with the recesses 1n the block, and on the slab being applied to the block, completely filling same and preventing end or sideways movement of the slab in all directions, the slab. pro r of a tough but fairly elastic ualili; and t e projections being of a tong or or harder quality, as set forth.

4. A paving block having in its top edges and at each corner se ental undercut recesses, the recesses opening on to the side and end faces of the block and those in the edges approximately semi-circular in plan and those at the corners bein rather more than a quarter of a circle an less than a semicircle in lan, in combination with a rubber slab of e proportions in plan to the top face of the b 0c and having on its underface and along its lower edges and bottom corners, segmental projections corresponding in shape and size with the recesses 1n the block, an on the slab being applied to the block, completely filling same and preventing end or sideways movement of the slab in all directions, said segmental projections having a stlgght inward set and requiring to be separa when being applied to the block, as set forth.

5. A paving block composed of a mouldable material, and having in its top edges and at each corner segmental undercut recesses, the recesses opening on to the side and end faces of the lock and those in the ed es approximately semi-circular inplan an those at the corners being rather more than a quarter of, a circle and less than a semi-circle in plan, in combination with a rubber slab of like proportions in plan to the top face of the block and having on its underiace and along its lower edges and bottom corners, segmental projections corresponding in shape and size with .the re cesses in the block, and on the slab being applied to the block, the said recesses and segmental projections mutually engaging during the moulding of the block, as set forth.

6. A paving block having an arched upper face and also having in its top edges and at each corner segmental undercut recesses, the recesses opening on to the side and end faces of the block and those in the of like proportions in plan to the top face ofthe block and having on its underface and along its lower edges and bottom corners, segmental projections correspnding in shape and size with the recesses in the'block, and on the slab beingapplied to the block, completely filling same and tpreventing end or sideways movement of e slab in all directions, as set forth.

7. A paving block having a corrugated top face, and also having along its top edges and at each corner segmental undercut recesses, the recesses opening on to the side and end faces of the block and those in the edges approximately semi-circular in plan and those at the corners beingrather more than a quarter of a circle and less than a semi-circle in plan, in combination with a rubber slab having a corrugated underface, and of like proportions in plan to the top face of the block and having on its underface and along its lower edges and bottom corners, segmental projections corresponding in she and size with the recesses in the block, and on the slab being applied to the block, completely filling same'and preventing end or sideways movement of the slab in all directions, as set forth.

8. A paving block having in its top edges and at each corner segmental undercut re-. cesses, therecesses opening on to the side and end faces of the block and those in the edges approximately semi-circular in plan and those at the corners being rather more than a quarter of a circle and less than a semi-circle in plan, in combination with a rubber slab of like r0 ortions in plan to the top face of the b 00 and having on its underface and along its lower edges and bottom corners, segmental projections corresponding in shape-and size with the recesses in the block, and on the slab being applied to the block, the form of the recesses and segmental projections .heing such-as to the edges of the slab being approximately afford an anchorage in vertical "planes at semi-circular in plan and those at the cor- 10 right angles to each other, asset forth ners being rather more than a quarter of'a 9. A rubber slab for use with a paving circle and less than a semi-circle in plan, as block having on its under face and along set forth. its lower edges and at its bottom corners, In testimony whereof I have signed my segmental dovetail projections, there being name to this specification. at leastsix projections in all and those at LUCIEN GAISMAN. 

